Screw conveyor for snow blowers



Oct. 4, 1966 P. E. VOHL 3,276,571

SCREW CONVEYOR FOR SNOW BLOWEIHS Filed Dec. 21, 1964 lNl/ENTCR Paul [@608 VOHL BQWWW AGENT United States Patent 1 Claim. or. 198-217) The present invention relates to snow blowers and, more particularly, to a screw convey-or for use in snow blowers.

A well-known type of snow blower consists of a scoop mounted forwardly of a motor vehicle and provided with one or more superposed, transversely arranged, screw conveyors mounted for continuous rotation within the scoop, in order to engage the snow and direct the same laterally towards the center of the scoop, or towards one or the other of its ends, in order to feed the snow to a blower which, under centrifugal force, ejects the snow at high speed through a chute.

The conventional screw conveyor is efficient in powdered snow, but cannot disintegrate, in an efficient manner, blocks of ice or of hardened snow, and these blocks often cause breakage of the blower fan or wedge the same against rotation.

Several attempts have been made in order to disintegrate blocks of ice, or of hardened snow, before they reach the blower of the machine; for instance, hammer-like masses have been secured to the spiral of the conveyor screw or snow-slicing blades have been positioned at least in front of the blower opening, but all these means considerably increase the cost of manufacture of the snow blower and often decrease the efliciency of the snow blower in dry and powdered snow, because these harnmers or slicing blades rotate in paths which are perpendicular to the axis of rotation of the conveyor screw and, therefore, do not serve by themselves to convey the snow laterally in the direction of the blower, but form an obstruction to the lateral movement of the snow.

Therefore, the general object of the present invention resides in the provision of a conveyor screw for snow removers or blowers, which is provided with means for slicing and disintegrating hardened snow and ice before the latter is fed to the blower, in order to prevent stoppage or breakage of the blower fan, and in which the conveyor screw remains eflicient in all conditions of snow, the means for slicing and disintegrating the blocks of ice or hardened snow form-ing no obstruction whatever to the lateral movement of the snow towards the blower opening.

Another object of the present invention resides in the provision of a conveyor screw of the character described, which is of very simple and relatively inexpensive construction.

Yet another object of the present invention resides in the provision of a conveyor screw of the character described, which is preferably reinforced to prevent bending of the spiral of the screw under the forces imparted thereto during slicing and disintegrating of ice or hardened snow.

The foregoing and other objects of the present invention will become more apparent during the following disclosure and by referring to the drawings, in which:

FIGURE 1 is a schematic side elevation of a snow blower mounted in front of a mot-or vehicle, the latter being shown in dot-and-dash lines;

FIGURE 2 is a front elevation of the snow blower;

FIGURE 3 is an elevation, partially in cross section and 3,276 ,5 71 Patented Oct. 4, 1966 on an enlarged scale, of a portion of the endless screw conveyor in accordance with the invention; and

FIGURE 4 is a partial cross-section, on an enlarged scale, of the spiral of the endless screw.

Referring more particularly to the drawings in which like reference characters indicate like elements throughout, reference letter A indicates a motor vehicle, such as a truck, farm tractor, or the like vehicle, in front of which is mounted a vertically adjustable scoop 1, of conventional construction, and constituted by a bottom wall 2, vertical lateral walls 3, a top wall 4, and a back wall 5. The scoop is completely open at the front thereof to receive snow which enters the scoop under the action of the forward movement of the vehicle A.

Two superposed convey-or screw-s 6 and 7 respectively are mounted within the scoop 1 transversely of the latter, the conveyor screws being horizontally disposed. The ends of the shafts of the screws are mounted in journal boxes 8 secured to the lateral walls 3.

The back wall 5 of scoop 1 is provided with an opening 9, preferably at the center of the scoop, and the conveyor screws 6 and 7 serve to feed the snow laterally towards the opening'9. The snow enters opening 9 of a casing 10 of a blower and is ejected by the blower fan 10', through a discharge chute 11 which is preferably arranged so as to be turned horizontally and vertically .to adjust the direction of snow ejection.

The upper conveyor screw 6 is of conventional 0on struction, comprising a shaft 12 mounted within journal boxes 8 and two spirals 13 and 14 surrounding and secured to the shaft 12, the spirals having opposed pitch and joining at the center oft-he shaft, as shown at 15. Shaft 12 is driven by a suitable transmission mechanism and engine 16, which is preferably mounted at the back of vehicle A.

Snow which enters scoop 1 is moved laterally of the scoop by endless screw 6 towards the center of the scoop where it is fed to the blower fan 10'.

Because screw 6 is disposed well above ground, it does not generally engage blocks of ice or hardened snow, but only engages powdered snow or wet snow. However, the lower conveyor screw 7, which is just above ground, is liable to engage blocks of ice or hardened snow.

This conveyor screw 7 is modified in accordance with the principle of the present invention. Conveyor screw 7 comprises a shaft 17, journalled in boxes 8 at its ends, in conventional manner, and driven by a conventional transmission mechanism, itself driven by engine 16.

Shaft 17 is surrounded by two spirally wound metal strips 18 and 19, of opposite inclination or pitch and joined at the center of the shaft at 20 opposite opening 9 of blower 10. The radially inner edge 21 of strips 18 and 19 is directly welded at 2-1 to shaft 17.

The major part 26 of the spiral 18 or 19 is straight when seen in cross-section and makes an angle with re- 7 s'pect to shaft 17. In accordance with the invention, the

radially outer marginal portion of each spiral sheet 18 and 19 is bent to form an external marginal part 22, which is at an angle with respect to main portion 23 of strips 18 and 1-9.

The angle between parts 22 and 23 is selected such that part 22 generates a cylindrical surface co-axial with shaft 17. The free edge of part 22 is preferably bevelled, as shown at 24, but can be a straight edge.

As a non-limitative example, spiral strips 18 and 19 may have an external diameter of 26'', margin-a1 portion 22 a width of 1" and bent to form an angle of 60 with main portion 23, the latter making in turn an angle of 30 with the axis of shaft 17.

Marginal portion 22 is obtained by subjecting sheets 18 and 19 to a rolling operation after said sheets have been formed into a spiral. Marginal portion 22 forms in .all cases an angle of less than 180 with main portion 23 at the face of the latter which is opposite shaft 17, or which makes an acute angle with the latter and, more generally, which is directed towards opening 9.

It is preferable, although not essential, to reinforce strips 18 and 19 by means of additional spirally wound sheets 25 and 26, respectively, the spiral of which having an external diameter less than main strips 18 and 19.

The radially outer edges 27 of strips 25 and 26 are welded to strips 18 and 19, respectively, in a zone just short of marginal portion 22 and at the face of strips 18 and 19, making an acute angle with shaft 17, that is to the internal faces of sheets 18 and 19.

The radially inner edge 28 of strips 25 and 26 is directly welded to shaft 17 in a zone longitudinally spaced from weld 21, whereby reinforcing strips 25 and 26 form an angle with shaft 17, which is less acute than the similar angles formed by sheets 18 and 19. Therefore, strips 25 and 26 form a V with main portions 23 of strips 18 and 19, as shown in FIGURE 3.

It should be noted that marginal portions 22 of strips 18 and 19 are directed towards opening 9 of blower during rotation of the conveyor screw 7. Marginal portions 22 engage blocks of ice, or hardened snow, from the side and move the same directly towards opening *9, while slicing said blocks of ice, or hardened snow.

The slicing action is efficient and the portions 22 do not form any obstruction against the movement of the snow laterally towards opening 9. Therefore, the efficiency of the snow blower is not decreased when the snow is completely dry and in powder form, or when the snow is wet.

Reinforcing strips 25 and 26 positively prevent bending of strips 18 and 19 under the forces exerted during slicing and disintegrating action. If desired, upper conveyor screw 6 can be replaced by a conveyor screw similar to screw 7, but, in practice, this has not been found necessary in normal snow conditions.

Bending of marginal 22 is effected by a rolling operation, as previously noted; this operation is very simple and, therefore, the endless screw 7 in accordance with the present invention is only slightly -more expensive to make than conventional endless screws such as screw 6.

While a preferred embodiment in accordance with the present invention has been illustrated and described, it is understood that various modifications may be resorted to without departing from the scope of the appended claims.

What I claim is:

A conveyor screw for snow blowers comprising a shaft, a first strip spirally wound around said shaft having its radially inner edge secured to said shaft, the main portion of said first strip being substantially straight in cross-section, the radially outer marginal portion of said first strip making an angle of less than with the face of said main portion, which is upstream with respect to the direction of rotation of said convey-or screw, said main portion being inclined at an acute angle with respect to said shaft and further including an additional reinforcing str-ip spirally wound around said shaft and having an external diameter less than the external diameter of said first strip, said additional strip secured to said first strip at its outer edge in a zone short of the outer margin-a1 portion of said first strip and secured to said shaft at its internal edge in a zone longitudinally spaced from the zone of fixation of the internal edge of said first strip to said shaft.

References Cited by the Examiner UNITED STATES PATENTS 2,320,723 6/ 1943 Gaylord 3743 2, 381,017 8/ 1945 Wandscheer.

FOREIGN PATENTS 192,948 ll/ 1957 Austria. 1,133,415 7/1962 Germany.

EVON C. BLUNK, Primary Examiner.

R. E. KRISHER, A. C. HODGSON,

Assistant Examiners. 

